Pick-up truck tie-down rails typically consist of tubes with bent ends or end brackets for attaching the rails to top ledges of cargo box side panels. They are usually mounted on cargo boxes by engaging stake or drilled holes. Tie-down rails known in the art suffer from a number of disadvantages such as, high tooling costs, excessive corrosion, lack of adaptability to alternate vehicles, inadequate structural stiffness, difficult-to-install procedures, misalignment and/or interference with cargo bed covers.
Many pick-up trucks have stake holes in tops of cargo boxes for attaching stakes and wooden rails. Although stakes and wooden rails are very seldom used, stake holes are convenient features for attaching tie-down rails. In many cases, drilled holes rather than stake holes are drilled to attach tie-down rails. In other cases, tie-down rails are welded to cargo boxes.
Drilled holes tend to weaken cargo boxes, induce corrosion and require special tools. Many tie-down rails are limited to one brand or model pick-up truck. This practice increases a manufacturer's tooling costs and inventory costs. Long spans between tie-down rail mountings of thin wall tubes result in excessive rail deflections and/or rail failures.
Okland U.S. Pat. No. 5,476,349; Davenport U.S. Pat. No. 5,827,024; Bundy U.S. Pat. No. 5,904,458 and Rowe U.S. Pat. No. 6,176,658 are exemplary of pick-up truck rails in the prior art. Okland 5,476,349 discloses a pair of fixed length tubular tie-down rails with separate die cast ends mounted in stake holes. The die cast ends require expensive molds. Moreover, the fixed length rails are specific to a single truck model.
Davenport 5,827,024 discloses a pair of fixed length one-piece tubular tie-down rails with bent ends. The rails are attached to a cargo box with bolts, drilled holes and brackets and are specific to a single truck model. Bundy 5,904,458 discloses a pair of pick-up truck rails mounted in drilled holes of a pick-up truck box. Rowe 6,176,658 discloses fixed length tie down rails bolted or welded to a pick-up truck box. None of the references are concerned with providing adequate clearances to cargo bed covers.